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From: syzbot <syzbot+a871c1e6ea00685e73d7@syzkaller.appspotmail.com>
To: alexandre.belloni@free-electrons.com, catalin.marinas@arm.com,
	 linux-kernel@vger.kernel.org, linux-mm@kvack.org,
	nicolas.ferre@atmel.com,  robh@kernel.org, sre@kernel.org,
	syzkaller-bugs@googlegroups.com
Subject: memory leak in vq_meta_prefetch
Date: Wed, 24 Jul 2019 12:18:07 -0700	[thread overview]
Message-ID: <00000000000052ad6b058e722ba4@google.com> (raw)

Hello,

syzbot found the following crash on:

HEAD commit:    c6dd78fc Merge branch 'x86-urgent-for-linus' of git://git...
git tree:       upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=15fffef4600000
kernel config:  https://syzkaller.appspot.com/x/.config?x=8de7d700ea5ac607
dashboard link: https://syzkaller.appspot.com/bug?extid=a871c1e6ea00685e73d7
compiler:       gcc (GCC) 9.0.0 20181231 (experimental)
syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=127b0334600000
C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=12609e94600000

The bug was bisected to:

commit 0e5f7d0b39e1f184dc25e3adb580c79e85332167
Author: Nicolas Ferre <nicolas.ferre@atmel.com>
Date:   Wed Mar 16 13:19:49 2016 +0000

     ARM: dts: at91: shdwc binding: add new shutdown controller documentation

bisection log:  https://syzkaller.appspot.com/x/bisect.txt?x=16c6d53fa00000
final crash:    https://syzkaller.appspot.com/x/report.txt?x=15c6d53fa00000
console output: https://syzkaller.appspot.com/x/log.txt?x=11c6d53fa00000

IMPORTANT: if you fix the bug, please add the following tag to the commit:
Reported-by: syzbot+a871c1e6ea00685e73d7@syzkaller.appspotmail.com
Fixes: 0e5f7d0b39e1 ("ARM: dts: at91: shdwc binding: add new shutdown  
controller documentation")

executing program
executing program
executing program
executing program
executing program
BUG: memory leak
unreferenced object 0xffff88811b327cc0 (size 32):
   comm "vhost-7201", pid 7205, jiffies 4294952492 (age 19.700s)
   hex dump (first 32 bytes):
     00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
     00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
   backtrace:
     [<000000009e106308>] kmemleak_alloc_recursive  
/./include/linux/kmemleak.h:43 [inline]
     [<000000009e106308>] slab_post_alloc_hook /mm/slab.h:522 [inline]
     [<000000009e106308>] slab_alloc /mm/slab.c:3319 [inline]
     [<000000009e106308>] kmem_cache_alloc_trace+0x145/0x280 /mm/slab.c:3548
     [<00000000ed2eec2d>] kmalloc /./include/linux/slab.h:552 [inline]
     [<00000000ed2eec2d>] vhost_map_prefetch /drivers/vhost/vhost.c:877  
[inline]
     [<00000000ed2eec2d>] vhost_vq_map_prefetch /drivers/vhost/vhost.c:1838  
[inline]
     [<00000000ed2eec2d>] vq_meta_prefetch+0x18e/0x350  
/drivers/vhost/vhost.c:1849
     [<000000009d9c11b8>] handle_rx+0x9d/0xc00 /drivers/vhost/net.c:1128
     [<000000008f883d86>] handle_rx_net+0x19/0x20 /drivers/vhost/net.c:1270
     [<00000000577ffdd8>] vhost_worker+0xc6/0x120 /drivers/vhost/vhost.c:519
     [<000000001201f3db>] kthread+0x13e/0x160 /kernel/kthread.c:255
     [<00000000093cd85a>] ret_from_fork+0x1f/0x30  
/arch/x86/entry/entry_64.S:352

BUG: memory leak
unreferenced object 0xffff88811b327cc0 (size 32):
   comm "vhost-7201", pid 7205, jiffies 4294952492 (age 20.600s)
   hex dump (first 32 bytes):
     00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
     00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
   backtrace:
     [<000000009e106308>] kmemleak_alloc_recursive  
/./include/linux/kmemleak.h:43 [inline]
     [<000000009e106308>] slab_post_alloc_hook /mm/slab.h:522 [inline]
     [<000000009e106308>] slab_alloc /mm/slab.c:3319 [inline]
     [<000000009e106308>] kmem_cache_alloc_trace+0x145/0x280 /mm/slab.c:3548
     [<00000000ed2eec2d>] kmalloc /./include/linux/slab.h:552 [inline]
     [<00000000ed2eec2d>] vhost_map_prefetch /drivers/vhost/vhost.c:877  
[inline]
     [<00000000ed2eec2d>] vhost_vq_map_prefetch /drivers/vhost/vhost.c:1838  
[inline]
     [<00000000ed2eec2d>] vq_meta_prefetch+0x18e/0x350  
/drivers/vhost/vhost.c:1849
     [<000000009d9c11b8>] handle_rx+0x9d/0xc00 /drivers/vhost/net.c:1128
     [<000000008f883d86>] handle_rx_net+0x19/0x20 /drivers/vhost/net.c:1270
     [<00000000577ffdd8>] vhost_worker+0xc6/0x120 /drivers/vhost/vhost.c:519
     [<000000001201f3db>] kthread+0x13e/0x160 /kernel/kthread.c:255
     [<00000000093cd85a>] ret_from_fork+0x1f/0x30  
/arch/x86/entry/entry_64.S:352



---
This bug is generated by a bot. It may contain errors.
See https://goo.gl/tpsmEJ for more information about syzbot.
syzbot engineers can be reached at syzkaller@googlegroups.com.

syzbot will keep track of this bug report. See:
https://goo.gl/tpsmEJ#status for how to communicate with syzbot.
For information about bisection process see: https://goo.gl/tpsmEJ#bisection
syzbot can test patches for this bug, for details see:
https://goo.gl/tpsmEJ#testing-patches


             reply	other threads:[~2019-07-24 19:18 UTC|newest]

Thread overview: 7+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-07-24 19:18 syzbot [this message]
2019-07-26 13:00 ` Catalin Marinas
2019-07-26 15:20   ` Dmitry Vyukov
2019-07-26 15:57     ` Catalin Marinas
2019-07-26 16:05       ` Dmitry Vyukov
2019-07-26 16:15         ` Catalin Marinas
2019-07-26 16:26           ` Dmitry Vyukov

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